Origin of the chemical elements in the universe

Determine the astrophysical origin of the chemical elements in the universe by identifying the nucleosynthesis processes and astrophysical sites responsible for their formation and quantifying their relative contributions to the observed elemental abundances across the periodic table.

Background

The paper discusses the synthesis of elements heavier than iron via neutron-capture processes and highlights the uncertainty surrounding the rapid neutron-capture (r) process and its astrophysical sites, such as neutron star mergers and certain core-collapse supernovae. While the slow neutron-capture (s) process near stability is comparatively well understood, the conditions and sites for the r process remain debated.

By measuring beta-decay half-lives and beta-delayed neutron emission probabilities for very neutron-rich nuclei near 78Ni, the work aims to reduce nuclear physics uncertainties that affect nucleosynthesis simulations. These improved inputs help refine models of element production, contributing to the broader effort to resolve the overarching question of how the chemical elements are formed and distributed in the universe.

References

The origin of the chemical elements in the universe is a long standing open question.

— Impact of newly measured $β$\nobreakdash-delayed neutron emitters around \myisoSimp{78}{Ni} on light element nucleosynthesis in the neutrino-wind following a neutron star merger  (2504.06008 - Tolosa-Delgado et al., 8 Apr 2025) in Main text, first paragraph after the abstract (Introduction), page 1

It remains unknown how binarity would affect the contribution of CCSNe to GCE.

— Supernova nucleosynthesis: a review  (2609.16584 - Zha et al., 15 Sep 2026) in Section 5.3, “Binarity, rotation and metallicity,” subsection “Binarity”

Although the potassium enhancement is therefore robust observationally, its nucleosynthetic origin remains unclear.

— High Resolution Spectroscopic Follow-up Observation Results for 13 EMP Candidates Selected by Narrow-band Photometry  (2609.09645 - Chen et al., 9 Sep 2026) in Section 6.1, “J2001-1215: a potassium-enhanced r-II star”